This is for one Shure PSM 600 UHF wireless in-ear monitoring system.Choose the desired system frequency from the drop-downs. The PSM 600 is a professional quality system, and operates on USA legal frequencies.The body pack receiver is solid metal, and has been professionally refinished to look like new. The P6T transmitter takes two input channels and transmits them both to the P6R body pack receiver.The user can control both the overall volume, and the mix of the two signals right at the body pack.You can use multiple receivers from the same transmitter, as long as all can use the same two channels being transmitted. Each system has the choice of two different frequencies for transmission, each in a separate UHF TV channel space.If in the USA, please check your area on the Shure Frequency Finder to determine the frequency groups that will work for you.This can be found on Shures USA website. If you need multiple systems in use at once, get each one in a different frequency.Also, you can get a PA760 antenna combiner (620-670MHz) to combine up to four transmitter outputs into a single antenna.This both amplifies and combines the signal. When coupled with a PA705 directional antenna, you get an extremely long range of operation.Both the PA760 combiner and the PA705 directional antenna are available in the drop-downs. Each system is in perfect condition, and comes ready to use with a P6T transmitter, P6R body pack receiver, 115VAC cord, and antenna.All you need are your earphones and an input signal source. These systems have been proven to be touring tough over the years, and can take extreme abuse and keep working. Im both an entertainer and an engineer, and I guarantee each system to operate as it should and to be as described. I gladly ship overseas! System can be set up to operate on 230VAC if needed!